MB95630H Series
246
FUJITSU SEMICONDUCTOR LIMITED
MN702-00009-1v0-E
CHAPTER 14 LIN-UART
14.7 Registers
14.7.2
LIN-UART Serial Mode Register (SMR)
The LIN-UART serial mode register (SMR) is used to select the operating mode,
specify the baud rate clock, and enable/disable output to the serial data and
clock pins.
■
Register Configuration
■
Register Functions
[bit7:6] MD[1:0]: Operating mode select bits
These bits select the operating mode.
Note: When the mode is changed during communication, exchanging on the LIN-UART is suspended and
the LIN-UART waits for the start of the next communication.
[bit5] OTO: One-to-one external clock input enable bit
This bit enables using the external clock directly as the LIN-UART serial clock.
In operating mode 2 (asynchronous), the external clock is used when the reception side of the serial clock is
selected (ECCR:MS = 1).
When the EXT bit in the SMR register is "0", the OTO bit is fixed at "0".
[bit4] EXT: External serial clock source select bit
This bit selects the clock input.
[bit3] REST: Reload counter restart bit
This bit restarts the reload counter.
bit
7
6
5
4
3
2
1
0
Field
MD1
MD0
OTO
EXT
REST
UPCL
SCKE
SOE
Attribute
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value
0
0
0
0
0
0
0
0
bit7:6
Operating mode
Details
Writing "00"
0
Asynchronous (Normal mode)
Writing "01"
1
Asynchronous (Multiprocessor mode)
Writing "10"
2
Synchronous (Normal mode)
Writing "11"
3
Asynchronous (LIN mode)
bit5
Details
Writing "0"
The baud rate generator (reload counter) is used as the LIN-UART serial clock.
Writing "1"
The external clock is used directly as the LIN-UART serial clock.
bit4
Details
Writing "0"
Selects the clock of the baud rate generator (reload counter).
Writing "1"
Selects the external serial clock source.
bit3
Details
Read access
The read value is always "0".
Writing "0"
Has no effect on operation.
Writing "1"
Restarts the reload counter.